This invention is for use in connection with a land irrigation system in which a moving water sprinkler line having a water inlet at one point extends laterally to and moves along the length dimension of a stationary water supply main having a plurality of water outlet valves at spaced points along its length. More particularly, the invention is directed to improved structure for supporting a connector pipe which provides a fluid path between the water supply main and the water sprinkler line.
When irrigating extensive areas of land, long sprinkler lines have been used for some time. Water has been supplied to these lines from buried pipes or mains having spaced risers projecting above the surface of the ground for connection to the sprinkler lines. Initially, each time a sprinkler line had to be moved, manual labor was required for this purpose. This was a laborious and time-consuming operation. Later, the sprinkler lines, which can reach a length of a quarter of a mile and more, were fitted with power-driven wheels to make them easier to move. Eventually, alignment systems were developed to accurately maintain the wheeled sprinkler lines in alignment and to keep them moving slowly along the desired path parallel to the direction of the main line. Flexible hoses or jointed pipes extended between the water inlet end of the sprinkler lines and the respectively connected riser.
Since the main line can be a pipe of eight or more inches in diameter and contain water under substantial pressure, the required size and strength of the flexible hoses and jointed pipe became extremely burdensome in manual operation. Proposals therefore have been made to facilitate connection of the sprinkling lines to successive risers with a minimum of manual effort. However, it is not believed that a commercially successful machine has previously been developed. Examples of such proposals are illustrated in U.S. Pat. No. 2,740,228 to Engel; U.S. Pat. No. Re. 26,285 to Stafford; U.S. Patent Nos. 3,381,893 and 3,446,434 to Smith. Such proposals provided for intermittent connection of the sprinkler line to the main line utilizing power assisted mechanical devices as the hoses or telescoping pipes were moved from riser to riser, with the sprinkler line continuing to move along at the desired rate.
In order to provide for a continuous source of water to the sprinkler line, U.S. Pat. No. 3,463,175 to Rogers; U.S. Pat. No. 4,036,436 to Standal; and Russian Pat. No. 434,918 proposed systems in which one riser is always connected to the sprinkler line, this being accomplished by having pipe or hose connections to the sprinkler line connect with mobile hydrant couplers which span three risers. By the arrangement employed in the Rogers and Standal patents, the forward hydrant coupler is disconnected from a first riser and proceeds to a second riser forward of the first riser. Upon connection of the forward hydrant coupler with the second riser, the trailing hydrant coupler is disconnected from its riser, which is prior in sequence to the first riser in the main line. The trailing hydrant coupler then travels to and is connected with the first riser. Apparently, the requirement for closely spaced risers, their unavailability of reliable water valves in the risers, and inadequate pipe connectors and controls contributed to the failure of these systems to gain commercial acceptance.
In the Russian patent, an elongated horizontal pipe having water valve connectors at each end is pivotally mounted at its center by a downturned ell on the forward end of a second, forwardly projecting elongated horizontal pipe which, in turn, is pivotally mounted at its rear end by an upturned ell to a sprinkler line carried by a mobile carriage. The carriage moves along a water main so that when the valve connector on one end of the first pipe is connected to a hydrant valve, the doubly pivoted mounting permits the other end of the first pipe to swing in an arc around the hydrant to bring the other valve connecting means into position to be connected to a second hydrant valve (apparently manually) before the first is disconnected. The entire water connecting mechanism is, therefore, cantilevered forward of the carriage. It appears that the illustrated system is inoperative which suggests that this device also may have never been actually used.
U.S. Pat. No. 3,729,016 to Von Linsowe discloses another irrigation system for continuously feeding water to a sprinkler line. This system is extremely complicated and requires twin main lines since the twin coupling devices for connecting the sprinkler line to the main line cannot pass each other. This proposal appears not to have been commercially accepted.